The evolution of technological augmentation is progressing faster than natural human biology, and it's clear that it won't be long until these physical enhancements will completely out-class natural human sports capabilities. The growing likelihood that, within the next decade, the fastest humans alive will be "disabled" holds the potential for profound "future shock." As I wrote about last year (in "The Accidental Cyborg"), young athletes facing the choice between rehabilitation and amputation for leg injuries are starting to pick amputation, knowing that the prosthetics could be an improvement, not an impairment.

I just read "Roo'd" - one of the only free books available for the iPhone at the moment, which hinges around this exact concept.

The main character is "disabled" in that he wasn't born with lower legs, but many of his peers elect to have theirs removed in favor of higher performance limbs. In the author's near-future world, sports become an mix of physical prowess and the skill of your doctors and engineers.

You can read the book here if you're interested:
http://www.wireless.is/projects/rood/

The six million dollar man or the bionic woman.